Attachment 1471908 Details for Bug 1607967 – Backport (part 1)

[patch] Backport (part 1)

0001-Fix-bad-ipv6-comparison.patch (text/plain), 2.44 KB, created by Lon Hohberger on 2018-07-31 18:58:51 UTC

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Creator: Lon Hohberger

Created: 2018-07-31 18:58:51 UTC

Size: 2.44 KB

patch

obsolete

>From 8649988de31cd283c16753bc4005f478bef13270 Mon Sep 17 00:00:00 2001
>From: Lon Hohberger <lon@metamorphism.com>
>Date: Fri, 27 Jul 2018 16:27:31 -0400
>Subject: [PATCH 1/3] Fix bad ipv6 comparison
>
>When performing DNS lookups, the source address from resolv.conf
>may have stray zeroes in it, or the address string returned from
>socket.recvfrom may. Purge them before comparing tuples.
>
>Resolves: rhbz#1607967
>
>Signed-off-by: Lon Hohberger <lon@metamorphism.com>
>Signed-off-by: Lon Hohberger <lhh@redhat.com>
>---
> eventlet/support/greendns.py | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
>diff --git a/eventlet/support/greendns.py b/eventlet/support/greendns.py
>index ea0924c..3ecbc9b 100644
>--- a/eventlet/support/greendns.py
>+++ b/eventlet/support/greendns.py
>@@ -35,6 +35,7 @@
> import struct
> import sys
> 
>+import eventlet
> from eventlet import patcher
> from eventlet.green import _socket_nodns
> from eventlet.green import os
>@@ -670,7 +671,12 @@ def udp(q, where, timeout=DNS_QUERY_TIMEOUT, port=53,
>         except:
>             af = dns.inet.AF_INET
>     if af == dns.inet.AF_INET:
>-        destination = (where, port)
>+        # Purge any stray zeroes in source address.  When doing the tuple comparison
>+        # below, we need to always ensure both our target and where we receive replies
>+        # from are compared with all zeroes removed so that we don't erroneously fail.
>+        #   e.g. ('00::1', 53, 0, 0) != ('::1', 53, 0, 0)
>+        where_trunc = dns.ipv6.inet_ntoa(dns.ipv6.inet_aton(where))
>+        destination = (where_trunc, port, 0, 0)
>         if source is not None:
>             source = (source, source_port)
>     elif af == dns.inet.AF_INET6:
>@@ -697,6 +703,13 @@ def udp(q, where, timeout=DNS_QUERY_TIMEOUT, port=53,
>                 # Q: Do we also need to catch coro.CoroutineSocketWake and pass?
>                 if expiration - time.time() <= 0.0:
>                     raise dns.exception.Timeout
>+                eventlet.sleep(0.01)
>+                continue
>+            if dns.inet.af_for_address(from_address[0]) == dns.inet.AF_INET6:
>+                # Purge all possible zeroes for ipv6 to match above logic
>+                addr = from_address[0]
>+                addr = dns.ipv6.inet_ntoa(dns.ipv6.inet_aton(addr))
>+                from_address = (addr, from_address[1], from_address[2], from_address[3])
>             if from_address == destination:
>                 break
>             if not ignore_unexpected:
>-- 
>2.13.6
>

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